Fitting assembly for deformably sealing corrugated tubing and a method for using the same

ABSTRACT

A fitting assembly for corrugated tubing comprising a body having first connecting means; an insert; locking means having second connecting means; and a resilient ring. The insert is sealingly engaged with the body and includes a transition area of increased outside diameter. The locking means includes an internally directed lip; a substantially conical section; and a retainer disposed between the second connecting means and the conical section. The first and second connecting means engage to removably secure the body to the locking means and to slide the ring within the conical section towards the lip forcing the ring to radially contract into a trough of a corrugated tube and sliding the corrugated tube onto the transition area. Further engagement of the first and second connecting means causes the ring to push on and collapse a ridge of the corrugated tube against the transition area creating a seal therebetween.

This application claims priority from provisional application serial No. 60/701,071, filed Jul. 19, 2005, the disclosure of which is incorporated by reference in its

FIELD OF THE INVENTION

This present invention is generally directed to a fitting assembly for sealing a corrugated tube and more specifically directed to sealing a portion of the fitting assembly with the corrugated tube by deformably compressing a ridge of the corrugated tube between an insert and a split ring.

BACKGROUND OF THE INVENTION

In plumbing applications, sections of pipe, tubing, or conduit are typically connected to one another to provide for the flow of fluids within a system. In connecting these sections, it is generally desirable to seal the connections in order to avoid or at least minimize the loss of fluid due to leaks or fugitive emissions. Various techniques exist for sealing the connections. Two of such techniques include welding and the use of adhesives.

When sections of pipe, tubing, or conduit are connected by welding, disconnection for service, repair, routine maintenance, or restructuring of the system often involves cutting or otherwise physically separating the sections. Disconnection usually involves cutting using high speed rotary tools. When the sections being cut apart are metal, sparks are often generated, which creates an undesirable condition. Even if the sections being cut are plastic, dust or flying debris may be generated. In either case, the integrity of the pipe, tubing, or conduit is compromised, and new sections must be fabricated and reinstalled.

When sections are connected with adhesives, disconnection may also involve cutting or some other physical method of separation (e.g., melting the adhesive), or it may involve effecting a chemical change to the adhesive. Melting the adhesive or using chemical techniques to separate the sections are often time consuming and costly practices. Reassembly of the system generally involves adhesively connecting new systems of pipe.

Therefore, connectors and fittings which provide releasable sealing capability are preferred for applications where disassembly is likely. Various connectors and fittings having releasable sealing capability are used to seal the outside surfaces of sections of pipe, tubing, or conduit with one another. However, in applications using corrugated tubing, inside and outside surfaces have ridges and troughs making sealing with prior art connectors and fittings ineffective. In addition, sealing on the outside surface of tubing is undesirable because walls of the tubing can become unintentionally distorted when the connector is secured thereby increasing the potential for leakage.

There is a need to provide a fitting or connector for releasably sealing corrugated tubing where the sealing is made inside the tubing. Prior art connectors and fittings for addressing these needs were either too expensive, inefficient, ineffective, or a combination of all of these. Based on the foregoing, it is the general object of the present invention to improve upon or overcome the problems and drawbacks of the prior art.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a fitting assembly for corrugated tubing includes a body having first connector, a bore, and a first shoulder positioned within the bore; an insert having a first external surface, a second external surface of increased outside diameter, and a transition area intermediate the first external surface and the second external surface, the insert being receivable in the bore of the body; a locking device having a through bore defining an internal surface, a second shoulder on the internal surface, a section of the internal surface further defining a substantially conical section, a retainer inwardly projecting from the internal surface, and a second connector cooperable with the first connector; and a resilient ring having a radially directed split therethrough for allowing the ring to radially flex in response to forces acting thereon, the ring being movably retained between the second shoulder and the retainer. The insert is sealingly engaged with the body.

In a second aspect of the present invention, an assembly for a fitting includes an adapter or other body having a first bore and first connector; an insert having a second bore and being sealingly engaged with the adapter; a nut or other locking device having a third bore and having a second connector engaged with the first connector; and a split ring positioned over the insert and between the nut and the adapter. When the first connector and the second connector are engaged and tightened, the split ring is urged against an outer surface of said insert. When a tube is held between the split ring and the outer surface of the insert, tightening of the first and second connectors causes the tube to deform against the outer surface of the insert to provide a seal.

In a third aspect of the present invention, a method of using a fitting assembly on a corrugated tube includes the steps of providing a fitting assembly for corrugated tube; abutting an insert of the fitting assembly against a shoulder of a body of the fitting assembly to sealingly engage the insert with the body; inserting a split ring into a conically-shaped cavity section of a locking device; sliding the corrugated tube through the locking device and through the ring; securing the body to the locking device; and using the split ring to deform the corrugated tube against an outer surface of the insert

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded cross sectional view of the fitting assembly for a corrugated tube.

FIG. 2 is a cross sectional view of a partially assembled fitting assembly for the corrugated tube showing the ring radially contracted.

FIG. 3 is a top view of an embodiment of the ring having contoured inside and sloping outside circumferential areas.

FIG. 4 is a cross sectional view of the ring illustrated in FIG. 3.

FIG. 5 is a cross sectional view of an enlarged section of the locking device illustrating the ring in a radially expanded state positioned over a ridge of the corrugated tube.

FIG. 6 is a cross sectional view of an enlarged section of the locking device illustrating the ring in a relaxed state positioned in a trough of the corrugated tube.

FIG. 7 is a cross sectional view of an enlarged section of the locking device, the insert and a portion of the body illustrating deformation of the corrugated tube.

FIG. 8 is a cross sectional view of body having the insert integral therewith.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As illustrated in FIG. 1, a fitting assembly for sealing an end of a corrugated tube to create a gas or liquid seal is shown at 10. The fitting assembly 10 includes a body 12, an insert 14, a locking device 16, and a ring 18 and can be used to connect lengths of corrugated tube, as an adapter to another coupling device or fitting, or to terminate a length of corrugated tube. The sealing is effected between an inner diameter of the corrugated tube and an outer surface of the insert 14 by deforming at least one of the corrugations, for example, by causing a peak of a corrugation to fold over onto an adjacent trough of the corrugation.

The body 12, which can be an adapter to connect the fitting assembly 10 to other devices or fittings, includes a first connector 20 comprising male threads, a bore 22, and a first shoulder 24 positioned within the bore. The bore 22 transitions to a reduced cross section 28 at the first shoulder 24. While the first connector 20 is shown with male threads, the present invention is not limited in this regard as other connecting means may also be utilized including but not limited to bayonet type connections. The body 12 may also have male threads 25 located on an end opposite the end at which the first connector is shown to facilitate the connection of the body to any other device having connectable female threads. In the alternative, the body 12 may be capped at the end opposite the end at which the first connector 20 is located.

The insert 14 is configured for receiving the corrugated tube (shown at 26 in FIG. 2) thereon. The insert 14 has a bore 29 and a transition area 32. The transition area 32 is defined by a curved surface that extends radially from a portion of the external surface of the insert to another portion of the external surface having an increased outside diameter. The insert 14 is coaxially received in the bore 22, and at least a portion of one end 34 of the insert 14 abuts at least a portion of the first shoulder 24. The insert 14 is sealingly engaged with the body 12. While the insert 14 is described as being sealing engaged with the body, the present invention is not limited in this regard as the insert may be sealingly engaged with the first shoulder 24, the reduced cross section 28, or a combination thereof.

The locking device 16, which may be a nut, has an internal surface 30 defining a through bore 37. A second connector 36 comprising female threads is disposed on the internal surface. A section of the internal surface 30 further defines a conical section 38. The locking device 16 also includes a second shoulder 40 and a retainer 42 disposed between the second connector 36 and the first section 38.

Referring to FIGS. 1-4, the ring 18 is made of a resilient material and has a radial split 48 therethrough for allowing the ring to radially flex in response to forces acting thereon. The ring 18 is retained between the second shoulder 40 and the retainer 42 and includes an inside surface 50 that engages a trough of the corrugated tube 26. An outside surface 52 of the ring 18 is angled to substantially complement the conical section 38. Although the inside surface 50 is shown as having a rounded contour to mate with the trough of the corrugated tube 26, the present invention is not limited in this regard, and the inside surface may be a flat or substantially flat wall with or without a suitable chamfer or radius.

Referring to FIG. 2, the fitting assembly 10 is assembled on the corrugated tube 26. The corrugated tube 26 is inserted into the locking device 16 and is retained therein via the ring 18. The corrugated tube 26 is also inserted over the insert 14, and the body 12 is releasably secured to the locking device 16 via the first connector 20 and the second connector 36. While the second connector 36 is described as having female threads, the present invention is not limited in this regard as other connecting means may also be utilized including but not limited to bayonet type connections.

Referring now to FIGS. 5-7, the ring 18 retains the corrugated tube 26 in the locking device 16 until the insert 14 (FIG. 7) is received in the end of the corrugated tube and the locking device is connected to the body 12. In FIG. 5, the ring 18 is shown abutted against the retainer 42 with the ring forced open by the ridge 54 of the corrugated tube 26 and expanded over the ridge. Referring now to FIG. 6, the ring 18 is shown in a contracted state (not forced fully open) so that an inside surface 50 thereof fits into a trough 56 of the corrugated tube 26. Referring now to FIG. 7, the ring 18 is shown abutting the second shoulder 40 with the ring contracted so that the inside surface 50 of the ring fits into the trough 56. When the body 12 and the locking device 16 are tightened together, the ring 18 is butted against the second shoulder 40 and the inclined surface of the transition area 32 is urged in the direction of the ring. As the body 12 and the locking device 16 are further tightened, the transition area 32 is further urged in the direction of the ring 18, and the corrugated tube 26 (namely, the ridge of the corrugation) is frictionally held on the inclined surface of the transition area 32. As the body and the locking device 16 are even further tightened, the transition area 32 is still further urged in the direction of the ring 18, and the ridge of the corrugation is forced by a side 58 of the ring to deform and fold over into the trough of the corrugation. When the ridge is fully folded and collapsed, the material of the corrugation is held against the transition area 32, thereby creating a seal.

Referring now to FIG. 8, a body 112 has an integral insert 114. The insert 114 is attached to the body 112 and coaxially aligned therewith. Because the outer diameter of the insert 114 is less than the outer diameter of the body 112, a transition area 132 is formed between the insert and the body. A connector 120 is disposed on the outer surface of the body 112 to facilitate the connection of the body and a locking device. The connector 120 may be male threads, which may be received by appropriate female threads on the locking device. The present invention is not limited in this regard, however, as other types of connections may be used to facilitate the connection of the body 112 and the locking device. Male threads 125 may also be disposed on an end of the body 112 opposite the end at which the insert 114 is integrally formed to allow for the connection of the body to another fitting or the like.

Referring generally to FIGS. 1-7 the insert 14, 114 is manufactured from a material softer than the corrugated tube 26. Similarly, the body 12, 112 is manufactured from a material softer than the corrugated tube 26. While the insert 14, 114 is said to be softer than the corrugated tube 26, the present invention is not limited in this regard as in another embodiment of the present invention the insert may be manufactured from a material which is as hard as or harder than the corrugated tube. Although the body 12, 112 is said to be softer than the corrugated tube 26, the present invention is not limited in this regard as in another embodiment the body may be manufactured from a material which is as hard as or harder than the corrugated tube.

Referring generally to FIGS. 1-7 a method of using the fitting assembly 10 on a corrugated tube 26 includes the steps of providing the fitting assembly; abutting the insert 14 against the first shoulder 24 to sealingly engage the insert with the body 12; contracting the ring 18 radially; inserting the ring through the retainer 42 into a cavity defined by the conical section 38, the second shoulder 40, and the retainer; releasing the ring into a relaxed and expanded state; sliding the corrugated tube through the locking device 16 and though the ring thereby abutting the ring against the retainer 42 and expanding the ring radially over at least one ridge 54 of the corrugated tube; positioning an inside surface 50 of the ring into a trough 56 of the corrugated tube; engaging the first and second connectors to removably secure the body to the locking device and to slide the ring within the cavity toward the second shoulder 40 forcing the ring to radially contract into the trough and sliding the corrugated tube onto the transition area; tightening the first and second connectors to abut the ring against a second ridge; and collapsing the second ridge against the transition area to seal one against the other.

Although the present invention has been disclosed and described with reference to certain embodiments thereof, it should be noted that other variations and modifications may be made, and it is intended that the following claims cover the variations and modifications within the scope of the invention. 

1. A fitting assembly for a corrugated tube, said fitting assembly comprising: a body having first connecting means, a bore, and a first shoulder positioned within said bore; an insert having a first external surface, a second external surface of increased outside diameter, and a transition area intermediate said first external surface and said second external surface, said insert being receivable in said bore; locking means having a through bore defining an internal surface, a second shoulder on said internal surface, a section of said internal surface further defining a substantially conical section, a retainer inwardly projecting from said internal surface, and a second connecting means cooperable with said first connecting means; and a resilient ring having a radially directed split therethrough for allowing said resilient ring to radially flex in response to forces acting thereon, said resilient ring being movably retained between said second shoulder and said retainer; wherein said insert is sealingly engaged with said body.
 2. The fitting assembly of claim 1, wherein at least a portion of one end of said insert abuts at least a portion of said first shoulder to effect said sealing engagement of said insert and said body.
 3. The fitting assembly of claim 1, wherein an opposing end of said insert is positioned to receive said corrugated tube thereon.
 4. The fitting assembly of claim 1, wherein said retainer is disposed between said second connecting means and said conical section.
 5. The fitting assembly of claim 1, wherein said resilient ring is radially expandable to fit over at least one ridge of said corrugated tube.
 6. The fitting assembly of claim 1, wherein said ring is radially contractable so that an inside surface of said resilient ring fits into a trough of said corrugated tube;
 7. The fitting assembly of claim 1, wherein said first and second connecting means engage to releasably secure said body to said locking means and to slide said resilient ring within said conical section towards said second shoulder, thereby forcing said resilient ring to radially contract into said trough and sliding said corrugated tube onto said transition area.
 8. The fitting assembly of claim 7, wherein further engagement of said first and second connecting means causes said resilient ring to collapse a ridge of said corrugated tube against a trough of said corrugated tube and holds said collapsed ridge against said transition area, the collapsing and holding of said ridge creating a seal between said transition area and said corrugated tube.
 9. The fitting assembly of claim 1, wherein said insert is integral with said body at least at said first shoulder.
 10. The fitting assembly for corrugated tubing of claim 1 wherein said insert is made from a material that is harder than said corrugated tube.
 11. The fitting assembly for corrugated tubing of claim 1 wherein said insert is made from a material that is softer than said corrugated tube.
 12. The fitting assembly of claim 1, wherein said first connecting means comprises male threads and wherein said second connecting means comprises female threads.
 13. The fitting assembly of claim 1 wherein said ring includes an inside surface contoured to mate with said trough and an outside angled surface matches said conical section.
 14. An assembly for a fitting, said assembly comprising: an adapter having a first bore and first connector; an insert having a second bore and being sealingly engaged with said adapter; a nut having a third bore, said nut having a second connector engaged with said first connector; and a split ring positioned over said insert and between said nut and said adapter; wherein when said first connector and said second connector are engaged and tightened, said split ring is urged against an outer surface of said insert.
 15. The assembly of claim 14, further comprising a corrugated tube inserted through said third bore in said nut and between said outer surface of said insert and said split ring.
 16. The assembly of claim 14, wherein said nut comprises a conical inner surface against which said split ring is positioned.
 17. The assembly of claim 16, wherein said conical inner surface is bounded at one end by a shoulder and bounded at a second end by a retaining ring.
 18. The assembly of claim 16, wherein said first connector and said second connector are engaged and tightened to cause said split ring to translate along said conical inner surface and to deform said corrugated tube to provide a sealed connection.
 19. The assembly of claim 18, wherein the deformation of said corrugated tube to provide said sealed connection comprises urging said split ring along said insert and over an area of said insert having an increased diameter.
 20. A method of using a fitting assembly on a corrugated tube, said method including the steps of: providing a fitting assembly for corrugated tubing, said fitting assembly comprising a body having first connecting means, a bore, and a shoulder; an insert having a transition area of increased outside diameter, locking means having an internal surface and a second shoulder, a section of said internal surface further defining a substantially conical section, said locking means further having second connecting means and a retainer inwardly projecting from said internal surface, wherein said retainer is disposed between said second connecting means and said conical section; and a resilient ring having a radially directed split therethrough for allowing said ring to radially flex in response to forces acting thereon; abutting said insert against said shoulder to sealingly engage said insert with said body; contracting said ring radially; inserting said ring through said retainer into a cavity defined by said conical section, said second shoulder, and said retainer; releasing the ring into an expanded and relaxed state; sliding said corrugated tube through said locking means and through said ring thereby abutting said ring against said retainer and expanding said ring radially over at least one ridge of said corrugated tube; positioning an inside surface of said ring in a trough of said corrugated tube; engaging said first and second connecting means to removably secure said body to said locking means and to slide said ring within said cavity toward said second shoulder forcing said ring to radially contract into said trough and sliding said corrugated tube onto said transition area; tightening said first and second connecting means to abut said ring against said a second ridge; and collapsing said second ridge against said transition area to seal said second ridge against said transition area. 